Search results: dietary guidelines

I was asked by a reporter yesterday for comment on the press release issued by the National Cattlemen’s Beef Association (NCBA) in response to USDA’s announced support of the Meatless Monday campaign.  

What? 

My immediate reaction: It’s pretty unbelievable that USDA would support Meatless Monday. Where’s the USDA statement? [see addition below]

The NCBA press release said:

The U.S. Department of Agriculture’s (USDA) recent announcement that the agency embraces the “Meatless Monday” concept calls into question USDA’s commitment to U.S. farmers and ranchers. USDA stated “one simple way to reduce our environmental impact while dining at our cafeteria is to participate in the “Meatless Monday” initiative.”

NCBA said Meatless Monday “is an animal rights extremist campaign to ultimately end meat consumption” and “NCBA will not remain silent as USDA turns its back on cattlemen and consumers.”

Without having seen what USDA said, I told the reporter:

If USDA is really supporting Meatless Monday, that’s big news. Historically, the USDA has worked hand in glove with the meat industry and has firmly resisted suggestions that it would be healthier for people and the planet to eat less meat.

The meat industry complained that the 2010 dietary guidelines pushed seafood and that meat got lost in protein in MyPlate, so they are supersensitive to this issue. Anyone who has ever been to a feedlot or industrial pig farm knows that the environmental issues are huge. You can smell them from miles away.

And what did the USDA actually say?  Oops.  Mistake.

According to the Boston Globe:

The Agriculture Department says a statement on its website encouraging its employees not to eat meat on Mondays was made without proper clearance.

The posting earlier this week was part of an internal newsletter that discusses how staff can reduce their environmental impact while dining at the agency’s cafeteria.

….USDA spokeswoman Cortney Rowe says the department does not endorse the “Meatless Monday” initiative, which is part of a global public health campaign.

Apparently, the USDA pulled the statement within minutes after the NCBA statement went out. 

How did USDA announce this to the public?  On Twitter!

USDA MT @usdapress: USDA does not endorse Meatless Monday. Statement on USDA site posted w/o proper clearance. It has been removed // @FarmBureau

 Food politics in action!

Addition, June 27: Here’s the original USDA Newsletter that caused all this fuss.  Scroll to page 3.

Dietary sodium continues to generate much talk but little action.

The CDC issued a recent Vital Signs report on dietary sodium with this graphic:

In translation from the data tables:

• 90% of Americans consume too much salt.
• 44% of salt comes from 10 foods: breads and rolls, cold cuts and cured meats, pizza, poultry, soups, sandwiches, cheese, pasta dishes, meat dishes, and snacks.
• 65% of salt comes from retail processed foods.
• 25% comes from food served at restaurants.
• 10% comes from salt added at the table.
• 10% occurs naturally in foods.
• $20 billion a year is the cost of salt-related chronic disease.

The bottom line?  Americans would be better off eating less salt.

But from the standpoint of the food industry, reducing dietary sodium is a big problem.  See, for example,  FoodNavigator-USA.com‘s recent articles about sodium in foods and health:

Sodium reduction: The science, the technology… and the business case It’s expensive, risky, and difficult, but manufacturers have made huge progress on sodium reduction in recent years. But how much further can they go, and where is the ROI if consumers are at best indifferent to their efforts, or at worst downright suspicious?.. Read Bakers on sodium reduction: We can’t afford to make products consumers won’t buy Reducing sodium is expensive and difficult, and many bakers are beginning to wonder whether it is worth investing millions into reformulating products that consumers do not want to buy, according to the Association of Bakers (ABA)… Read Risks of slashing sodium levels in cheese could outweigh benefits, US researcher A prominent US researcher says that government pressure to cut sodium in cheese could have serious food safety, taste and labeling consequences, and questions the necessity of such a move given minimal evidence of positive health effects and muted consumer demand… Read Sodium reduction: To boldly go… lower and lower Food manufacturers are under increasing pressure to reduce sodium, but surveys suggest many shoppers are, well, not that bothered. So where does this leave firms plugging sodium reduction solutions? Elaine Watson asks Mariano Gascon, R&D chief at seasonings, flavors and spice specialist Wixon for his take on it… Read Law professor: Sodium reduction only works if there is a level playing field If consumers are not demanding lower-sodium products, and the government does not mandate reductions, the food industry has “no incentive to be at the forefront of change”, according to one legal expert… Read National Dairy Council: Low sodium cheese is not taking the market by storm While cheese makers remain committed to salt reduction, demand for low-sodium cheese remains pretty lackluster, according to the National Dairy Council (NDC)… Read Academic: Government sodium targets are incompatible with rest of dietary guidelines Further evidence that government healthy eating guidelines are more ‘aspirational’ than achievable has been uncovered by researchers testing how easy it is to meet low sodium targets and get the rest of the nutrients we need… Read IFT urges government to take a cautious approach to sodium reduction The Institute of Food Technologists (IFT) has submitted comments to government agencies suggesting that actions to reduce sodium should not go “too far, too fast”, and has raised concerns about consumer acceptance and the safety of reduced sodium foods… Read American Heart Association blasts industry sodium reduction skeptics Suggestions by the Salt Association and other industry associations that sodium reductions could hurt rather than improve health are “not supported by science”, the American Heart Association (AHA) has insisted… Read ‘Processed’ foods are often high in sodium – but what’s a processed food? About 75% of the sodium in our diets comes from processed foods. It’s a regularly cited figure – but what exactly is a ‘processed’ food? Consumers might be surprised… Read

But this one just in:

•  Salt intake during pregnancy may alter heart structure of offspring: Rat study

My monthly (first Sunday) Food Matters column in the San Francisco Chronicle:

Q: What’s going on with the farm bill? Any chance for improving it?

A: I wish your question had an easier answer. The farm bill has to be American special-interest politics at its worst.

As Stacy Finz has been reporting in the main news and Business sections of The Chronicle, the failure of the recent super-deficit reduction plan also brought an end to a secret committee process for writing a new farm bill. Now Congress must follow its usual legislative procedures. The farm bill is again open for debate.

Advocacy is much in order. The farm bill is so enormous, covers so many programs, costs so much money and is so deeply irrational that no one brain – certainly not mine – can make sense of the whole thing.

It is all trees, no forest. The current bill, passed in 2008, is 663 pages of mind-numbing details about programs – hundreds of them – each with its own constituency and lobbyists.

The farm bill was designed originally to protect farmers against weather and other risks. But it grew piecemeal to include programs dealing with matters such as conservation, forestry, biofuels, organic production and international food aid.

The most controversial programs cover food commodities – corn, soybeans, wheat, rice, cotton, sugar and dairy – but lesser-known provisions support smaller industries such as honey or Hass avocados.

The elephant in the farm bill is SNAP, the Supplemental Nutrition Assistance Program (formerly food stamps). Fully 80 percent or more of farm bill expenditures go for SNAP.

This year, SNAP costs ran about $6 billion a month, and they are rising in today’s depressed economy. In contrast, commodity subsidies cost “only” about $8 billion a year. Crop insurance adds $4.5 billion, and conservation about $5 billion. Everything else runs in the millions, not billions, mere nothings in comparison to SNAP’s $70 billion 2011 expenditures.

SNAP judgements

What, you might ask, is SNAP doing in the farm bill? Think: logrolling.

Members of Congress who represent farm states need urban votes to pass subsidies. Urban members need farm votes to protect SNAP. This deal works, and both sides like the unsavory system just as it is.

As for irrationality: At a time when preventing obesity heads the public health agenda and reducing greenhouse gases is an international priority, the farm bill firmly protects the status quo.

It promotes production of commodities, but does little to link agricultural policy to policies that promote health or environmental protection. Although the Dietary Guidelines and MyPlate strongly promote consumption of fruits and vegetables, the farm bill inconsistently considers these foods as horticulture or specialty crops that do not merit subsidies or government-supported insurance. Indeed, many farm bill provisions discourage production of fruits and vegetables.

Overall, the farm bill must be seen as an inequitable means to protect the income of the largest and richest industrial producers of food commodities. It has little to do with serious efforts to protect conservation of natural resources, support rural communities or promote sustainable farming practices that maintain soil quality and mitigate climate change. Nor does it address the real needs of low-income communities.

The current bill favors large farms over small ones, intensive rather than sustainable production methods, and some states and regions over others. It actively promotes risk-taking; the government covers the costs.

It ignores food safety. It promotes production of inefficient biofuels. It does nothing to promote sustainable farming practices in this or any other country. And because it rewards farmers for overproducing commodities, it gets the United States in trouble with international trading partners.

Worst of all, the bill is inherently undemocratic. It is so opaque that nobody in Congress or anywhere else can possibly grasp its entirety. Its size and complexity make it especially vulnerable to influence by lobbyists for special interests and by the corporations most generous with campaign contributions.

Pro and con arguments

Its defenders argue that the present system works pretty well in ensuring productivity, global competitiveness and food security. Tinkering with it, they claim, will not make much difference and could do harm.

I disagree. It needs more than tinkering. Americans need farm policy to be brought into line with health and climate-change policy, and now is our chance.

Those of us who believe that food systems should be healthier for people and the planet have been handed an opportunity to rethink farm bill programs and to make the processes for its development more democratic.

Groups such as the Environmental Working Group ( www.ewg.org) and National Sustainable Agriculture Coalition (sustainableagriculture.net) have been hard at work on these issues. Join them, speak up, and get busy.

This article appeared on page G – 4 of the San Francisco Chronicle

Yesterday’s New York Times’ report (in which I am quoted) reminds me that it’s time I commented on the astonishing dispute about potatoes in school meals.

On October 20, 2009, the Institute of Medicine (IOM) issued a report on nutrition standards for school meals.  It recommended that school meals be aligned with the Dietary Guidelines for Americans.  To do so, the IOM said USDA should

Adopt standards for menu planning that increase the amounts of fruits, vegetables and whole grains; increase the focus on reducing the amounts of saturated fat and sodium provided; and set a minimum and maximum level of calories.

To do that, the IOM said USDA should establish (1) weekly requirements for dark green and orange vegetables and legumes, and (2) limits—of one cup a week—on starchy vegetables such as white potatoes, corn, lima beans, and peas.

The IOM’s quite sensible rationale?  To encourage students to try new vegetables in place of the familiar starchy ones.

In January this year, the USDA proposed new nutrition standards for school meals based on the IOM report.  These included the IOM’s recommendation of no more than one cup a week of starchy vegetables.

Please note: the proposal does not call for elimination of starchy vegetables.  It calls for a limit of two servings a week (one cup is two servings).

What’s wrong with that?  Plenty, according to the potato industry, which stands to sell fewer products to the government and could not care less about spreading the wealth around to other vegetable producersPotato lobbyists went to work (apparently the sweet corn, lima bean, and pea industries do not have the money to pay for high-priced lobbying talent).  The Potato Council held a press conference hosted by Senators from potato-growing states.

The result?  The U.S. Senate added an amendment to the 2012 agriculture spending bill blocking the USDA from “setting any maximum limits on the serving of vegetables in school meal programs.”

Mind you, I like potatoes.  They are thoroughly delicious when cooked well, have supported entire civilizations, and certainly can contribute to healthful diets.  Two servings a week seems quite reasonable.  So does encouraging consumption of other vegetables as well.

But what’s at stake here goes way beyond the choice of one vegetable over another.

At issue is Senate micromanagement of nutrition standards under pressure from food industry lobbyists. 

• Lobbyists have no business trying to influence nutrition standards.
• The Senate has no business micromanaging nutrition standards.

This is one more—and a particularly egregious—example of undue industry influence on federal dietary guidance policy.  It is just plain wrong.

Does a name change make a difference?  The Grocery Manufacturers Association (GMA) and the Food Marketing Institute (FMI) evidently think so.

They are changing the name of their preemptive front-of-package (FOP) labeling scheme from “Nutrition Keys” to “Facts Up Front.”

The new name comes with a new website, a new organization (FactsUpFront.org), and a $50 million marketing campaign.

Its purpose?  As I have discussed on more than one occasion (see here and here, for example), GMA and FMI are engaged in a blatant, in-your-face attempt to undermine the FDA’s current efforts to rationalize FOP labeling.

The FDA engaged the Institute of Medicine (IOM) to produce two research reports on FOP labeling.  The first IOM report, released a year ago, concluded that FOP labels should disclose only calories and three “bad-for-you” nutrients: saturated fats, trans-fats, and sodium.  I thought the report made sense but that the omission of sugars was a mistake.

The IOM also said that information about good-for-you nutrients—protein, fiber, vitamins, and minerals—would only confuse consumers and would be likely to encourage food companies to unnecessarily fortify products with these nutrients as a marketing strategy.

The second IOM report, according to press accounts, is due out sometime in October.  The FDA is waiting for this report before starting rulemaking on FOP labels, an interminable process at best.

In the meantime, the food industry has jumped the gun.  The Facts Up Front website justifies this scheme on the basis of the Dietary Guidelines:

To ensure that consumers receive consistent and reliable information, the labeling system also adheres to current guidelines and regulations from FDA and USDA Food Safety and Inspection Services.

…Manufacturers may also choose to include information on up to two “nutrients to encourage.” These nutrients – potassium, fiber, protein, vitamin A, vitamin C, vitamin D, calcium and iron – are needed to build a “nutrient-dense” diet, according to the Dietary Guidelines for Americans.

Yes they are, but not on the front of food packages.  It’s obvious why GMA and FMI are doing this—they know that nobody will look at or understand the label.

But they should not be doing this.  It is the wrong thing to do.

On the topic of name changes:  The American Dietetic Association (ADA) has just changed its name to the Academy of Nutrition and Dietetics (AND).  I’m not a member of the ADA, can only speculate on what this is about, and have no comment.

 

I keep getting questions about saturated fat.  Does it really pose a health risk?  If so, how serious a risk?  And isn’t eating real food OK even if it contains saturated fat?  Good questions.  Here are a couple of recent examples:

Reader #1: I think that the idea that saturated fats in meat and dairy are unhealthful is errant, based on correlative – not causative – scientific studies…I propose that instead of demonizing one nutrient over another, we favor whole, high-quality foods of both animal and plant origin…designed by nature (and thousands of years of trial and error) to meet the needs of their respective populations. What do you say?

Reader #2: I wonder how the government can be so focused on low-fat milk. Is that really such a huge problem? Isn’t the bigger problem that the state of NY is telling people pretzels make a healthy snack? Isn’t it soda and cheese doodles and eating every dinner from a box that is the problem? Whole milk, really? I’d appreciate your clarity on this… we are full fat milk and cheese people, and all of this perplexes me.

I can understand why anyone might be confused about saturated fat.  Food fats are complicated and it helps to be a biochemist (as I once was) to sort out the issues related to degree of saturation and whether the omegas are 3, 6, or 9 (I explain all this in the chapter on fats and in an appendix to What to Eat).

And yes, the science is complex and sometimes seems contradictory but scientific committees for the past 50 years have concluded one after another that substituting other kinds of fatty acids for saturated fatty acids would reduce levels of blood cholesterol and the risk for coronary heart disease.

And no, those scientists cannot have all be delusional or paid off by the meat or dairy industries.  They—like scientists today—mostly call the science the way they see it.

What makes the research especially hard to sort out is that all food fats—no exceptions—are mixtures of saturated, unsaturated, and polyunsaturated fatty acids (just the proportions differ), that some saturated fatty acids raise blood cholesterol levels more than others do, and that one kind—stearic acid—seems neutral with respect to blood cholesterol.

But overall, the vast majority of expert committees typically conclude that we would reduce our heart disease risks if we kept intake of saturated fat below 10% of calories, and preferably at or below 7%.   On average, Americans consume 11-12% of calories from saturated fat, which doesn’t sound too far off but the average means that many people consume much more.

As is often the case with studies of single nutrients, research sometimes comes to different conclusions.  Several studies—all quite well done—have appeared just in the last year or so.

One of these is a meta-analysis (a review of multiple studies). It concludes:

…there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD [coronary heart disease] or CVD [cardiovascular disease]. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat [my emphasis].

What saturated fat gets replaced with is the subject of three other well conducted studies that come to a different—the mainstream—conclusion.  One, another recent meta-analysis, confirms decades of previous observations (sorry about the annoying abbreviations):

These findings provide evidence that consuming PUFA [polyunsaturated fatty acids] in place of SFA [saturated fatty acids] reduces CHD events in RCTs [randomized clinical trials]. This suggests that rather than trying to lower PUFA consumption, a shift toward greater population PUFA consumption in place of SFA would significantly reduce rates of CHD.

Translation: replacing saturated fats with polyunsaturated fats would be healthier.

Another meta-analysis comes to the same conclusion:

The associations suggest that replacing SFAs with PUFAs rather than MUFAs [monounsaturated fatty acids] or carbohydrates prevents CHD over a wide range of intakes.

A very recent consensus statement concludes:

the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol [the “bad” kind] and is likely to produce a reduction in CHD incidence of ≥2–3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index.

The advisory committee to the 2010 Dietary Guidelines for Americans reviewed this and other research relating saturated fatty acids to heart disease risk and concluded:

Cholesterol-raising SFAs, considered SFA minus stearic acid…down-regulate the low density lipoprotein (LDL) receptor by increasing intracellular cholesterol pools and decreasing LDL cholesterol uptake by the liver.

The committee’s research review addressed the question, “What is the Effect of Saturated Fat Intake on Increased Risk of Cardiovascular Disease or Type 2 Diabetes, Including Effects on Intermediate Markers such as Serum Lipid and Lipoprotein Levels?”  It judged the evidence strong

that intake of dietary SFA is positively associated with intermediate markers and end point health outcomes for two distinct metabolic pathways:

1) increased serum total and LDL cholesterol and increased risk of CVD and

2) increased markers of insulin resistance and increased risk of T2D [type-2 diabetes]. Conversely, decreased SFA intake improves measures of both CVD and T2D risk.

The evidence shows that 5 percent energy decrease in SFA, replaced by MUFA or PUFA, decreases risk of CVD and T2D in healthy adults and improves insulin responsiveness in insulin resistant and T2D individuals.

How much saturated fat might increase the risk of heart disease or type-2 diabetes depends on how much you eat as well as what you eat.

What to do to reduce your dietary risks for heart disease?  Take a look at the top 15 sources of saturated fats in U.S. diets:

• Regular cheese
• Pizza
• Grain-based desserts (cakes, cookies, pies, pop-tarts, donuts, etc)
• Dairy desserts
• Chicken and chicken mixed dishes (e.g. fingers)
• Sausage, franks, bacon, and ribs
• Burgers
• Mexican mixed dishes
• Beef and beef mixed dishes
• Reduced fat (not skim) milk
• Pasta and pasta dishes
• Whole milk
• Eggs and egg mixed dishes
• Candy
• Butter
• Potato/corn/other chips
• Nuts/seeds and nut/seed mixed dishes
• Fried white potatoes

Explanation: These foods do not necessarily have the most saturated fat.  If the list surprises you, recall that all food fats have some saturated fats.  These foods are leading sources because they contain some saturated fat and many Americans eat them.

It is surely no coincidence that these foods are also among the leading sources of calories in U.S. diets.  The health effects of diets, let me repeat, have to do with quantity as well as quality.

If you do not habitually eat most of the foods on this list, and are not gaining weight, saturated fatty acids are much less likely to be a problem for you.

And just because saturated fats raise the risk of heart disease does not mean they are poisons.   Eat fats.  Just not too much.

 

 

 

I’ve just turned in the copy-edited manuscript of Why Calories Count: From Science to Politics (pub date March 2012) and now have time to catch up on some questions:

Q. I was recently given to read a book titled “The China Study” which is based on research conducted in 1970’s in China by Dr. Colin Campbell. His main conclusion is that eating dairy and meat causes cancer. His resolution is that a plant-based diet (i.e. vegan) is the (only?) healthy diet for humans. This book has made strong enough of a point to convince several of my friends to “convert” to a vegan diet in order to save their health. Could you share some comments on the validity of the research and conclusions this book presents with regards to detrimental effects of dairy and meat on human health?

A. Campbell makes a forceful argument based on his interpretation of the research and on case studies of people whose diseases resolved when they became vegans. And yes I’ve seen Dr. Campbell’s new movie, Forks over Knives. The first half is a terrific introduction to how the current food environment promotes unhealthy eating.  The second half promotes Dr. Campbell’s ideas about the hazards of meat and dairy foods.

Whether you agree with these ideas or not, the film is well done and worth a look.

Some scientists, however, interpret the research as demonstrating that people are healthier when they eat dairy foods.  For example, the enormous consensus report on diet and cancer risk from the American Institute for Cancer Research and the World Cancer Research Fund concluded in 2007 that eating lots of red meat and processed meat is convincingly associated with an increased risk of colorectal cancer (but no others).

On the other hand, they found dairy foods to be associated with a decrease in the risk of colorectal cancer.  They found limited and less convincing evidence that dairy foods might decrease the risk of bladder cancer but increase the risk of prostate cancer.

How to make sense of this?  These are two food groups in the diets of people who consume many kinds of foods and who do many things that might increase or decrease cancer risk.  Given this complexity, one food or food group seems unlikely to have that much influence on cancer when considered in the context of everything else people eat and do.

Nutrition research, as I am fond of saying, is difficult to do and requires interpretation. Intelligent people can interpret the studies differently depending on their point of view.

The new Dietary Guidelines say to cut down on saturated fats. Those are most plentiful in meat and dairy foods (plant foods have them, but in smaller amounts). Pretty much everyone agrees that plant-based diets promote health/  But whether they have to be 100% plant-based is highly debatable.

The new USDA MyPlate food guide suggests piling plant foods—fruit, vegetables, and grains—on 75% of your plate so the argument is really about what goes on the remaining 25%, what USDA calls the  “Protein” section. You can put beans in that quarter if you don’t want to eat red meat, poultry, or fish.

Q. I’d love to hear your take on the recent walnut flap [accusations that the FDA now considers walnuts to be drugs].  I suspect walnuts got caught with such offenders as Pom, Froot Loops, and Juicy-Juice, but I’d love to find out what the FDA actually said about this. For some odd reason I don’t believe the article is presenting the whole truth.

A. This is a health claims issue. The FDA is not saying walnuts are drugs. It is saying that Diamond Walnut is claiming walnuts as drugs on package labels. How so?

The labels say the omega-3 fatty acids in walnuts may help lower cholesterol; protect against heart disease, stroke and some cancers (e.g. breast cancer); inhibit tumor growth; ease arthritis and other inflammatory diseases; and even fight depression and other mental illnesses. These are disease claims for which the FDA requires scientific substantiation.

The company’s petition did not provide that substantiation so the FDA issued a warning letter. In general, you should be skeptical any time you see a nutritional factor advertised for its ability to prevent or treat such a broad range of problems.

Q. A question about sugar and how it is counted: My books say: 4 g = 1 teaspoon = 15 calories. My Illy Caffe says 10 g of sugar, but 50 calories. Ingredients: coffee, sugar, potassium bicarbonate, potassium citrate. If the drink is 50 calories, shouldn’t it say 12 g or more for the sugar listing?

A. Sugar should be the only ingredient that has calories in this coffee but I’ve seen calorie lists that say 5 calories per gram for sugars. Food companies have some leeway in the way they compute calories. Illy may be using a method that gives 5 rather than 4. But the difference between 40 and 50 is hardly measurable and I wouldn’t worry about amounts this small, annoying as imprecise figures may seem.

I complained to Scientific American about one of its blog posts about salt, which I viewed as rather one-sided.  The result was a conversation with Michael Moyer that ended up in the form of a Q and A.  I did not have a chance to review it before it was posted, so please see addendum at the end). 

The Salt Wars Rage On: A Chat with Nutrition Professor Marion Nestle

A researcher explains why there may never be a good study on whether excess dietary salt causes hypertension and heart disease

By Michael Moyer | Thursday, July 14, 2011

 Is salt bad for us? In just the past few months researchers have published seemingly contradictory studies showing that excess sodium in the diet leads to heart disease, reduces your blood pressure, or has no effect at all. We called Scientific American advisory board member Marion Nestle, a professor of Nutrition, Food Studies, and Public Health at New York University and the author of Food Politics, to help parse the latest thinking regarding salt and heart health.leads to heart disease, reduces your blood pressure, or has no effect at all. We called Scientific American advisory board member Marion Nestle, a professor of Nutrition, Food Studies, and Public Health at New York University and the author of Food Politics, to help parse the latest thinking regarding salt and heart health.

[An edited transcript of the interview follows.]

I understand this area is controversial.

Hugely.

Could you take us through some of the controversy?

If you talk to any kidney specialist or anybody working on hypertension they will tell you that the first thing they do is try to lower the amount of salt their patients are eating because it helps with blood pressure control. But if you do a clinical trial where you try to put large amounts of people on a low-salt diet, you just don’t see much difference between the people who say they eat a lot of salt and the people who say they don’t eat a lot of salt. In clinical trials the relationship doesn’t show up.

Why not?

Two reasons: One that it’s impossible to put a population of people on a low-salt diet. Roughly 80 percent of the salt in the American food supply is in foods before people eat them—either in processed food or in restaurant food. Because so much salt is added to the food supply and because so many people eat out, it’s impossible to find a population of people who are eating a low-salt diet. They basically don’t exist.

In the one comparative epidemiological study they did some years ago—the Intersalt study—they managed to find two populations of people in remote areas of the jungle someplace who weren’t eating a lot of processed foods and who weren’t eating in restaurants. They were on a low-salt diet, and they never developed hypertension.

So in that trial did they put one group on a high-salt diet and put one on a low-salt diet?

No, no, no. It wasn’t a comparative trial. They just looked at the amount of salt that populations were eating and the amount of hypertension that they had. Only in these two populations were there very low rates of hypertension. With everybody else the salt intake was so high that they couldn’t see any difference between high and higher.

So except for people living in the jungle somewhere, there aren’t any populations on Earth that are eating a low amount of salt?

Not anymore. Maybe we used to be, but not anymore. We have a global food supply, so it’s impossible to do a really careful study.

What’s the other issue?

Not everybody responds to a low-salt diet. There’s a proportion of people in the population who are sensitive to salt—if you lower their intake of salt, then their blood pressure goes down. There’s another (probably larger) percentage of the population who doesn’t respond. They are people who can eat as much salt as they want and still their blood pressure is low.

So you have this curious anomaly where whenever you do a clinical trial you get these complicated, difficult-to-interpret results that don’t show much of an effect. But everybody who works with patients who have hypertension think they do better [on a low-salt diet]. And every committee, body, and group that has ever in my lifetime considered whether salt has anything to do with hypertension says, “yes,” and has recommended salt reduction as a public health measure. That’s the curious situation that we are in.

There’s one other wrinkle and has to do with people’s taste for salt. Campbell’s soup, for example, just announced yesterday that can’t sell low-sodium soups and so they’re adding salt back. And part of the reason they can’t sell it is that if you’re on a high-salt diet, food that isn’t salty tastes terrible to you. And if you’re on a low-salt diet it takes three to six weeks to get accustomed to being on a low-salt diet and then everything you eat tastes salty. And so the more salt in the food supply the more salt people need to bring the flavor you associate with salt. That complicates things, too.

So from a public health standpoint, if you want to deal with the percentage of the population that seems to be extremely responsive to a low-salt diet what you want to do is get the sodium level in the food supply as low as you can. And that makes the people who sell salty food go nuts. And it makes the people who like salty foods go nuts. They think the food tastes bland. And so there are different stakeholders in this system who have very different views and that accounts for the level of passion, I think, in a situation where the science is murky.

Couldn’t you just make the case that people should eat fewer processed foods?

Well what about restaurants? I’m a food professional. I eat out professionally.

Well chefs need to make their food taste good—otherwise people won’t go to their restaurant.

No, they need to make the food taste good by their standard. And chefs, because they’re dealing with a great deal of salt in their food, tend to raise the sodium level. It just goes up and up and up and up. As they get more used to a certain level of salt taste it no longer tastes salty to them and they have to raise it. So the pressure is to raise the salt in the food supply. And reducing it is very difficult.

So you advocate regulation to limit the amount of salt in restaurants?

Yeah, I do. Certainly for processed food. I think everybody would be healthier if they ate less salt. You can always add salt if you don’t think it’s salty enough, whereas I can’t take it away if it’s presented to me. And that’s the dilemma. And the ferocity of the arguments gets into the whole question of personal responsibility and “nanny state” and all of these other enormous debates that really don’t get at the public health question. And the public health question is hard to resolve because the science is really difficult to do.

Couldn’t you imagine a study where you look at sodium levels in urine, which is a direct measure of salt intake, and correlate that with hypertension?

Yeah they’ve done that, and they don’t see any difference in hypertension rates. The reason is that the baseline [level of salt intake] is so high that it doesn’t make any difference. To suggest that people get down to 1,500 mg a day—the recommended level—would be really really hard, and that level may be too high. And it’s unclear that that’s the right level because you can’t do a really decent dose response, and because people vary so much.

Will there ever be a good study?

I don’t know!

Is it possible that this represents the limits of science? It’s black hole event horizons and salt intake?

It may be. It very well may be. Or the science that we have is completely adequate and we already have the answer. I was once at a sodium meeting at which there were a bunch of statisticians. And I left with the statisticians and they said that “anyone who thinks that salt has anything to do with hypertension is delusional.” And that was on the basis on the clinical trials that show so little. And yet every single committee that has dealt with this question says, “We really need to lower the sodium in the food supply.” Now either every single committee that has ever dealt with this issue is delusional, which I find hard to believe—I mean they can’t all be making this up—there must be a clinical or rational basis for the unanimity of these decisions.

But that’s the thing—these committees should be able to point to the evidence that supports their recommendations. But they seem to rely so much on anecdote and individual experience.

Or on some clinical trials that everybody argues about. Everybody argues about every clinical trial no matter what the conclusion. So I find the whole thing completely fascinating. I don’t think anybody can underestimate the difficulty of doing nutritional research. Because people aren’t eating just sodium. They’re eating sodium in food. And it may be that high-sodium diets are a marker for some other things in the food supply or it may be that the physiological differences are so profound that you just don’t get clean results. That human variation is so great. I don’t know the answer to that. I just know it works for me. That’s anecdotal. With an “n” of one.

Addendum

If I had been given the opportunity to review this before it was posted, I would have edited it carefully.  Yes, this is the way I talk but I don’t think what I said reads clearly in print.  In reading over this piece, I think it may give the wrong impression of my views on how expert committees decide on salt recommendations.  The piece may give the impression that committees make dietary recommendations basied on anecdotal evidence, not science.  That’s not true.  They base their recommendations on their interpretation of the experimental and clinical evidence, including that from clinical trials.

For example, the Advisory Committee for the 2010 Dietary Guidelines concluded that “a strong body of evidence has documented that in adults, as sodium intake decreases, so does blood pressure.”  Was this committee delusional in viewing the evidence as strong?  I don’t think so.